ENS 55505
ENS Event | |
|---|---|
04:00 Aug 4, 2021 | |
| Title | Part 21 - Actuator Failure |
| Event Description | The following is a summary of the report provided by Flowserve:
Flowserve - Limitorque was notified by Framatome Nuclear Parts Center that TVA Browns Ferry Nuclear (BFN) plant reported that a Limitorque SMB actuator had failed to operate electrically. It was noted by TVA that the actuator failure was discovered following a recent steam leak in the vicinity of the actuator. Investigation at BFN identified the failed component as the DC electric motor. The motor was removed from the actuator and disassembled by BFN personnel. Subsequently the motor was returned to Flowserve - Limitorque for evaluation. The subject motor is designated as a safety related basic component. Flowserve' s investigation, in conjunction with the motor original equipment manufacturer (OEM), has concluded that during manufacture, the subject motor sustained mechanical damage to the stator assembly field coil which led to the failure. As the dedicating entity, Flowserve is reporting this deviation in the assembly of the motor as a defect per the requirements of 10 CFR 21. Flowserve's investigation has concluded that this manufacturing defect is an isolated occurrence. No other instances of similar mechanical damage to the stator field coil insulation of Peerless DC motors have been observed or reported. The defect is specific to a quantity of one motor originally supplied to Framatome NPC on Limitorque Order Number 164879.001. This motor was subsequently supplied to the TVA Browns Ferry Nuclear Plant. Identification of Component: Limitorque part # P-140-851-18F0 Description: Peerless 7.5 ft-lb, 250 volt DC motor Serial Number: E18-99091-2 manufactured in August 2018 Corrective Actions to Date: The motor OEM is implementing additional assembly controls and quality control verification concerning the installation and final appearance of the coil support rod that damaged the stator field coil. This action, to be completed by October 15, 2021 will supplement the existing inspection checks on fully assembled motors, which includes insulation resistance tests and high potential tests which verify the integrity of the motor insulation system. Technical questions concerning this notification can be directed to Kyle Ramsey, Engineering Specialist, Flowserve - Limitorque Actuation Systems: kramsey@flowserve.com |
| Where | |
|---|---|
| Flowserve Lynchburg, Virginia (NRC Region 1) | |
| Organization: | Flowserve |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+1472.07 h61.336 days <br />8.762 weeks <br />2.016 months <br />) | |
| Opened: | Chris Shaffer 12:04 Oct 4, 2021 |
| NRC Officer: | Brian Lin |
| Last Updated: | Oct 4, 2021 |
| 55505 - NRC Website | |
Flowserve with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 571672024-06-07T04:00:0007 June 2024 04:00:00
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